PM Modi and President Putin interacted via video-conferencing and assured that the Kudankulam is one of the safest atomic plants in the world.

Speaking on the occasion from New Delhi, PM Modi said Kudankulum 1, an Indo-Russian project, is an important addition to the continuing efforts to scale up production of clean energy in India.

"I have always deeply valued our friendship with Russia and it is fitting that we jointly dedicate Kudankulam Nuclear Power Plant (KNPP) Unit 1. This also signals our joint commitment to build pathways of partnership for green growth," he said. President Putin, speaking from Moscow, said it is a big event for all.

"The power plant is updated with most modern Russian technologies. It is not just construction and commissioning of the power plant. It is well known that Russia is one of the world leaders in nuclear technology and we are glad to share with our Indian colleagues our technology," he said.

Joining the event from Chennai, Chief Minister Jayalalithaa said Kudankulam plant is a "monument commemorating the long standing, abiding and deep friendship between Russia and India and that she had supported implementation of the project, at Kudankulam in Tamil Nadu's Tirunelveli district, all through her 10 years in office".

The plant had been set up using the Russian VVER type reactors based on enriched uranium and its second unit was expected to start operations later this year.

The completion of the first unit was delayed in view of strident protests by local people, who raised safety concerns, before it became operational.

The Pressurised Water Reactor (PWR) VVER-1000 had gone critical in July 2014 and the commercial operations started from December 31 the same year, with the unit coming to the aid of the then power starved Tamil Nadu.

The Cumulative Generation of Unit I since the date of commercial operation is 6,498 million units (MU) with its capacity factor peaking to 100 per cent in June this year. The prime minister said the dedication of KNPP-I marked another historic time line in Indo-Russia relations.

"In successful completion, it is not only another fine example of the strength of our special and privileged strategic partnership, it is also a celebration of our binding friendship. It is only a start of our cooperation in this field," he said. PM Modi said five more units of 1,000 MW each would be built at the KNPP.

"Today's event is also a joyful occasion for the team of Indian and Russian scientists and technicians. We salute their dedication and hard work and congratulate them for the fruits of their labour," he said.

Chief Minister Jayalalithaa said nuclear power was "clean, green and firm power", which a rapidly growing state like Tamil Nadu, aspiring for higher growth rates and shared prosperity, really needed.

"The dedication of the KNPP is a major milestone in Indo-Russian cooperation. Throughout my 10 years in office as the Chief Minister of Tamil Nadu I have always extended support to the implementation of the Kudankulam project while at the same time laying focus on allaying the fears of the local people by convincing them about its safety," she said.